#include <std_include.hpp>
#include "launcher/launcher.hpp"
#include "loader/loader.hpp"
#include "loader/component_loader.hpp"
#include "game/game.hpp"

#include <utils/flags.hpp>
#include <utils/io.hpp>
#include <utils/string.hpp>

#include <DbgHelp.h>

#include <version.hpp>

const char* get_current_date()
{
	auto now = std::chrono::system_clock::now();
	auto current_time = std::chrono::system_clock::to_time_t(now);
	std::tm local_time{};

	(void)localtime_s(&local_time, &current_time);

	std::stringstream ss;
	ss << std::put_time(&local_time, "%Y%m%d_%H%M%S");

	const auto result = ss.str();
	return utils::string::va("%s", result.data());
}

LONG WINAPI exception_handler(PEXCEPTION_POINTERS exception_info)
{
	if (exception_info->ExceptionRecord->ExceptionCode == 0x406D1388)
	{
		return EXCEPTION_CONTINUE_EXECUTION;
	}

	if (exception_info->ExceptionRecord->ExceptionCode < 0x80000000 ||
		exception_info->ExceptionRecord->ExceptionCode == 0xE06D7363)
	{
		return EXCEPTION_CONTINUE_SEARCH;
	}

	MINIDUMP_EXCEPTION_INFORMATION exception_information =
	{
		GetCurrentThreadId(), exception_info, FALSE
	};

	const auto type = MiniDumpIgnoreInaccessibleMemory
		| MiniDumpWithHandleData
		| MiniDumpScanMemory
		| MiniDumpWithProcessThreadData
		| MiniDumpWithFullMemoryInfo
		| MiniDumpWithThreadInfo;

	CreateDirectoryA("minidumps", nullptr);
	const auto* file_name = utils::string::va("minidumps\\iw6-mod_%s_%s.dmp", SHORTVERSION, get_current_date());
	constexpr auto file_share = FILE_SHARE_READ | FILE_SHARE_WRITE;

	const auto file_handle = CreateFileA(file_name, GENERIC_WRITE | GENERIC_READ, file_share, nullptr,
		CREATE_ALWAYS, NULL, nullptr);

	if (!MiniDumpWriteDump(GetCurrentProcess(), GetCurrentProcessId(),
		file_handle, static_cast<MINIDUMP_TYPE>(type),
		&exception_information, nullptr, nullptr))
	{
		char buf[4096]{};
		sprintf_s(buf, "An exception 0x%08X occurred at location 0x%p\n", exception_info->ExceptionRecord->ExceptionCode, exception_info->ExceptionRecord->ExceptionAddress);
		game::show_error(buf);
	}

	CloseHandle(file_handle);
	TerminateProcess(GetCurrentProcess(), exception_info->ExceptionRecord->ExceptionCode);

	return EXCEPTION_CONTINUE_SEARCH;
}

[[noreturn]] void WINAPI exit_hook(const int code)
{
	component_loader::pre_destroy();
	std::exit(code);
}


BOOL WINAPI system_parameters_info_a(const UINT uiAction, const UINT uiParam, const PVOID pvParam, const UINT fWinIni)
{
	component_loader::post_unpack();
	return SystemParametersInfoA(uiAction, uiParam, pvParam, fWinIni);
}

FARPROC WINAPI get_proc_address(const HMODULE hModule, const LPCSTR lpProcName)
{
	if (lpProcName == "GlobalMemoryStatusEx"s)
	{
		component_loader::post_unpack();
	}

	return GetProcAddress(hModule, lpProcName);
}

launcher::mode detect_mode_from_arguments()
{
	if (utils::flags::has_flag("dedicated"))
	{
		return launcher::mode::server;
	}

	if (utils::flags::has_flag("multiplayer"))
	{
		return launcher::mode::multiplayer;
	}

	if (utils::flags::has_flag("singleplayer"))
	{
		return launcher::mode::singleplayer;
	}

	return launcher::mode::none;
}

FARPROC load_binary(const launcher::mode mode)
{
	loader loader;
	utils::nt::library self;

	loader.set_import_resolver([self](const std::string& library, const std::string& function) -> void*
	{
		if (library == "steam_api64.dll")
		{
			return self.get_proc<FARPROC>(function);
		}

		if (function == "ExitProcess")
		{
			return exit_hook;
		}

		if (function == "SystemParametersInfoA")
		{
			return system_parameters_info_a;
		}

		if (function == "GetProcAddress")
		{
			return get_proc_address;
		}

		return component_loader::load_import(library, function);
	});

	std::string binary;
	switch (mode)
	{
	case launcher::mode::server:
	case launcher::mode::multiplayer:
		binary = "iw6mp64_ship.exe";
		break;
	case launcher::mode::singleplayer:
		binary = "iw6sp64_ship.exe";
		break;
	case launcher::mode::none:
	default:
		throw std::runtime_error("Invalid game mode!");
	}

	std::string data;
	if (!utils::io::read_file(binary, &data))
	{
		throw std::runtime_error(
			"Failed to read game binary! Please select the correct path in the launcher settings.");
	}

#ifdef INJECT_HOST_AS_LIB
	return loader.load_library(binary);
#else
	return loader.load(self, data);
#endif
}

void remove_crash_file()
{
	const utils::nt::library self;
	auto name = self.get_name();
	name = std::filesystem::path(name).replace_extension("").generic_string();

	utils::io::remove_file("__" + name);
	utils::io::remove_file("__iw6mp64_ship");
	utils::io::remove_file("__iw6sp64_ship");
}

void enable_dpi_awareness()
{
	const utils::nt::library user32{"user32.dll"};
	const auto set_dpi = user32
		                     ? user32.get_proc<BOOL(WINAPI *)(DPI_AWARENESS_CONTEXT)>("SetProcessDpiAwarenessContext")
		                     : nullptr;
	if (set_dpi)
	{
		set_dpi(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
	}
}

void limit_parallel_dll_loading()
{
	const utils::nt::library self;
	const auto registry_path = R"(Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\)" + self.
		get_name();

	HKEY key = nullptr;
	if (RegCreateKeyA(HKEY_LOCAL_MACHINE, registry_path.data(), &key) == ERROR_SUCCESS)
	{
		RegCloseKey(key);
	}

	key = nullptr;
	if (RegOpenKeyExA(
		HKEY_LOCAL_MACHINE, registry_path.data(), 0,
		KEY_ALL_ACCESS, &key) != ERROR_SUCCESS)
	{
		return;
	}

	DWORD value = 1;
	RegSetValueExA(key, "MaxLoaderThreads", 0, REG_DWORD, reinterpret_cast<const BYTE*>(&value), sizeof(value));

	RegCloseKey(key);
}

void apply_environment()
{
	char* buffer{};
	std::size_t size{};
	if (_dupenv_s(&buffer, &size, "GHOSTS_INSTALL") != 0 || buffer == nullptr)
	{
		return;
	}

	const auto _ = gsl::finally([&]
	{
		std::free(buffer);
	});

	SetCurrentDirectoryA(buffer);
	SetDllDirectoryA(buffer);
}

int main()
{
	AddVectoredExceptionHandler(0, exception_handler);
	SetProcessDEPPolicy(PROCESS_DEP_ENABLE);

	FARPROC entry_point;
	enable_dpi_awareness();

	// This requires admin privilege, but I suppose many
	// people will start with admin rights if it crashes.
	limit_parallel_dll_loading();

	std::srand(static_cast<std::uint32_t>(time(nullptr)) ^ ~(GetTickCount() * GetCurrentProcessId()));

	{
		auto premature_shutdown = true;
		const auto _ = gsl::finally([&premature_shutdown]()
		{
			if (premature_shutdown)
			{
				component_loader::pre_destroy();
			}
		});

		try
		{
			apply_environment();
			remove_crash_file();

			if (!component_loader::post_start()) return 0;

			auto mode = detect_mode_from_arguments();
			if (mode == launcher::mode::none)
			{
				const launcher launcher;
				mode = launcher.run();
				if (mode == launcher::mode::none) return 0;
			}

			game::environment::set_mode(mode);

			entry_point = load_binary(mode);
			if (!entry_point)
			{
				throw std::runtime_error("Unable to load binary into memory");
			}

			if (!component_loader::post_load()) return 0;

			premature_shutdown = false;
		}
		catch (std::exception& ex)
		{
			game::show_error(ex.what());
			return 1;
		}
	}

	return static_cast<int>(entry_point());
}

int WINAPI WinMain(HINSTANCE, HINSTANCE, PSTR, int)
{
	return main();
}